Some known bearing assemblies for wheel bearings utilized in trucks comprise two inner rings or races having different bore diameters. A frustum-shaped connecting piece or spacer is disposed between the differently-sized inner rings and serves to set the spacing of the inner rings in the axial direction. The inner rings and spacer are mounted on a non-driven wheel axle or axle spindle having an outer shape that generally corresponds to the shape of the inner bores of the inner rings and spacer. Roller elements are disposed between the inner rings, which contact the axle spindle and do not rotate during driving, and a corresponding set of outer rings or races, thereby forming inboard and outboard roller bearings. These roller bearings enable a wheel hub coupled to a wheel to rotate about the non-driven axle spindle when the vehicle is driven.
To simplify mounting of the wheel mount on the wheel axle, the inner ring having the smaller diameter is disposed, with respect to the insertion direction of the wheel axle, on the forward or front side of the wheel mount and the inner ring having the larger diameter is disposed on the rearward side of the wheel mount. The circumferences of the wheel axle or axle spindle correspond to the bore diameters of the inner rings and the spacer, such that, during mounting of the wheel mount on the wheel axle, the segment of smaller circumference is initially guided through the larger-diameter inner ring and the spacer. This mounting procedure can thus be performed in a relatively simple manner. As soon as the axle spindle segment having the smaller circumference is completely inserted into the inner ring having the smaller diameter, the frustum-shaped segment of the axle spindle is located in the corresponding frustum-shaped segment of the spacer and the segment of the axle spindle having the larger circumference is located in the inner ring of larger diameter.
In such a three-part construction, axial and/or radial shifting or displacement of the inner rings relative to the spacer may not be sufficiently restricted or prevented during the mounting procedure. Further, if the junction of the respective inner rings and the spacer is not relatively smooth, the axle spindle could bump against the spacer or the smaller inner ring during insertion into the wheel bearing assembly, which would hinder the mounting procedure.